Compact filters based on dual‐mode gap waveguide cavities and 3D printing technology

The design of compact dual‐mode/band filters based on gap waveguide and 3D printing technology is presented in this paper. The spatial power divider is designed to arrange the external coupling. And the multi‐slot middle plate is devised to manage the coupling between the dual‐mode cavities, introducing the non‐resonating modes to produce additional transmission zeros and improving the selectivity. Moreover, the dual‐mode/band filters structure are built up and optimized for 3D printing technology. Finally, the fabricated filters are measured to verify the design.